I do agree that third-world hookers are being exploited by Western, and increasingly Indian, African, and Chinese guys. And I find it laughable when I speak to Western fellas who get so enraged about the perceived social injustice in the West yet feel no guilt when shagging the arse off a teenage street urchin in Pattaya.
But, I would say that exploitation is much, much less than others would have you think. Let's face it, it's a fantastic story to spin for a hooker. It really elicits sympathy. 99% of hookers will tell you they don't like to do it with other guys but they need the money. That's exploitation of a hooker. However, they really like having sex with you for money. That's exploitation of a customer.
Capitalism by its very nature is exploitative. That's a cop-out. Humanity by its very nature is exploitative.